)NN 


22 

.242 


43 

n  o  >  s^s 
CONNECTICUT 

Agricultural  Experiment  Station 

NEW  HAVEN,  CONN. 


BULLETIN  242  NOVEMBER,  1922 

BEING  A 

Report  on  Commercial 
Insecticides  and  Fungicides 

1922 


I.     The  Examination  of  Some  Materials  Sold  as  Insecticides  and 
Fungicides.    By  E.  M.  Bailey  and  R.  E.  Andrew. 

II.     Recent  Developments  in  the  Use  of  Insecticides. 

By  W.  E.  Britton. 


CONTENTS 

Page 

Materials    Examined    147 

Methods  of  Analysis   148 

Paris  Green  149 

Lead  Arsenate 150 

Materials  other  than  Paris  Green  and  Lead  Arsenate  : 

Calcium  and  Copper-Calcium  Arsenates    152 

Bordeaux  Mixtures,  etc 153 

Nicotine  Products  and  Tobacco   154 

Hellebore 156 

Miscellaneous  Materials   156 

Discussion  of  Uses,  etc 163 


The  Bulletins  of  this  Station  are  mailed  free  to  citizens  of  Connecticut 

who  apply  for  them,  and  to  other  applicants  as  far 

as  the  editions  permit. 


CONNECTICUT  AGRICULTURAL  EXPERIMENT  STATION 

OFFICERS  AND  STAFF 
November,  1922. 


BOARD  OF  CONTROL. 
His  Excellency,  Everett  J.  Lake,  ex-officio,  President. 

James  H.  Webb,  Vice-President Hamden 

George  A.  Hopson,  Secretary Mount  Carmel 

E.  H.  Jenkins,  Director  and  Treasurer New  Haven 

Joseph  W.  Alsop Avon 

Charles  R.  Treat ' Orange 

Elijah  Rogers Southington 

Edward  C.  Schneider   Middletown 


Administration. 


STAFF. 
E.  H.  Jenkins,  Ph.D.,  Director  and  Treasurer. 
W.  L.  Slate,  Jr.,  B.Sc,   Vice-Director. 
Miss  L.  M.  Brautlecht,  Bookkeeper  and  Librarian. 
Miss  J.  V.  Berger,  Stenographer  and  Bookkeeper. 
William  Veitch,  In  charge  of  Buildings  and  Grounds. 
Chemistry. 

Analytical  Laboratory.   E.  M.  Bailey,  Ph.D.,  Chemist  in  Charge. 
R.    E.   Andrew,    M.A. 
C.  E.   Shepard 
Owen  L.  Nolan 
Harry  J.  Fisher,  A.B. 
Frank  Sheldon,  Laboratory  Assistant. 
V.  L.  Churchill,  Sampling  Agent. 
Mrs.  B.  P.  Storrs,  Clerk. 


Biochemical 
Laboratory. 

Botany. 


Entomology. 


Forestry. 


Plant  Breeding. 

In  charge  of  the 
Tobacco  Station. 


-.  Assistant  Chemists. 


T.  B.  Osborne,  Ph.D.,  D.Sc,  Chemist  in  Charge. 

G.  P.  Clinton,  Sc.D.,  Botanist. 

E.  M.  Stoddard,  B.S.,  Pomologist. 

Miss  Florence  A.  McCormick,  Ph.D.,  Pathologist. 

G.  E.  Graham,  General  Assistant. 

Mrs.  W.  W.  Kelsey,  Secretary. 

W.   E.   Britton,   Ph.D.,  Entomologist;  State  Entomologist. 
B.  H.  Walden,  B.Agr.,    M.  P.  Zappe,  B.S.,  ^Assistant 
Philip  Garman,  Ph.D.,  J      Entomologists 

John  T.  Ashworth,  Deputy  in  Charge  of  Gypsy  Moth  Work. 
Samuel  T.  Sealy,  Deputy  in  Charge  of  Mosquito  Control. 
Miss  Gladys  M.  Finley,  Stenographer. 

Walter  O.  Filley,  Forester. 

A.  E.  Moss,  M.F.,  Assistant. 

H.  W.  Hicock,  M.F.,  Assistant. 

Miss  Pauline  A.  Merchant,  Stenographer. 

Donald  F.  Jones,  S.D.,  Plant  Breeder. 
P.   C.  Mangelsdorf,  B.S.,  Assistant. 

G.  H.  Chapman,  Ph.D.,  Windsor, 


I.    The  Examination  of  Some  Materials  Sold  as  Insecticides 

and  Fungicides. 

By  E.  M.  Bailey  and  R.  E.  Andrew. 

No  laws  have  been  enacted  in  this  State  to  control  the  manu- 
facture, sale  or  distribution  of  insecticides  and  fungicides.  An 
Act  concerning  the  testing  and  labeling  of  disinfectants  was  passed 
by  the  legislature  in  19 17,  and  it.  is  probable  that  such  materials 
can  be  controlled  also  by  the  provisions  of  our  food  and  drug 
law  under  the  definition  of  the  term  "drug";  but  the  law  cannot 
be  interpreted  to  include  insecticides  and  fungicides.  The  terms 
of  the  Federal  Insecticide  Act  of  1910  amply  provide  for  the 
control  in  interstate  commerce  of  materials  to  be  used  for  insecti- 
cidal  or  fungicidal  purposes,  but  do  not  operate  for  the  control 
of  such  materials  as  are  now,  or  may  be,  made  and  sold  within 
this  state. 

The  general  and  increasing  use  of  spraying  materials  for  the 
control  of  insect  pests  and  fungus  diseases  makes  the  question  of 
the  composition  of  such  materials  of  interest  and  importance.  A 
bulletin1  on  this  subject  was  issued  by  this  Station  in  1907,  but 
no  systematic  survey  has  been  made  since  that  time.  Occasional 
samples  of  substances  used  for  spraying  or  dusting  purposes  have 
been  examined  for  individuals  interested,  but  these  have  been  pub- 
lished in  regular  reports  from  this  laboratory,  together  with  other 
miscellaneous  materials.  Such  scattering  analyses,  so  far  as  they 
are  of  interest,  have  been  collected  and  are  presented  here  in  addi- 
tion to  the  results  of  new  analyses. 

MATERIALS  EXAMINED. 
A  classification  of  the  materials  examined  is  as  follows : 

Samples  Collected  in  1922. 

Paris   Green    8 

Lead  Arsenate    16 

Calcium  Arsenate  1 

Copper-Calcium  Arsenate  2 

Bordeaux  Mixture  3 

Bordeaux  Mixture — Paris  Green 2 

Bordeaux  Mixture — Lead  Arsenate   3 

Bordeaux  Mixture — Zinc  Arsenate >.  1 

Nicotine  Products  and  Tobacco  14 

Hellebore 5 

Miscellaneous 25 

^onn.  Agr.  Sta.,  Bull.  157,  Sept.,  1907. 


I48  CONNECTICUT  EXPERIMENT  STATION  BULLETIN   242. 


Cited  from  Earlier  Reports  of  This  Station,  But 
Subsequent  to  1907. 
Paris  Green,  Lead  Arsenate  and  Miscellaneous  


Total  from  all  sources 


IS 


95 


Of  samples  secured  this  year,  49  were  collected  by  our  Station 
agent,  Mr.  Churchill,  and  the  remainder  were  submitted  by  pur- 
chasers or  others  interested.  A  considerable  number  have  been 
referred  to  us  by  the  department  of  entomology  of  this  Station. 


METHODS  OF  ANALYSIS. 

The  methods  used  for  the  analysis  of  these  preparations  are 
those  authorized  by  the  Association  of  Official  Agricultural 
Chemists  unless  otherwise  stated. 


RESULTS  OF  EXAMINATION. 

For  the  sake  of  uniformity  where  like  materials  are  tabulated 
together,  dissimilar  chemical  terms  used  in  statements  of  guaranty 


Table  I.    Analyses  of 


Station  No. 

\ 

Date. 

18445 

1922 

18091 

1922 

18458 

1922 

18099 

1922 

l8lOO 

1922 

18443 

1922 

18090 

1922 

18455 

1922 

17320 

1921 

i93J9 

1921 

Brand,  Manufacturer    or  Distributor. 


Sampled  by  Station  Agent: 
James  A.  Blanchard  Co.,  New  York.    Lion  Brand 
Bob-White    Chemical    Corp.,    New    York.      Bob- 
White    

Devoe  &  Raynolds  Co.,  Inc.,  New  York.    Devoe. 

The  Glidden  Co.,  Cleveland.     Glidden   

Morris  Herrmann  &  Co.,  Chicago.    Hi-Grade.... 

Interstate  Chem.  Co.,  Jersey  City.     Hillside 

Leggett  &  Brother,  New  York.  Anchor  Brand.. . 
The  Sherwin-Williams  Co.,  Cleveland   

Sampled  by  Purchaser: 

Leggett's    

Raynold's  


PARIS  GREEN. 


149 


have  been  reduced  to  a  common  basis.  Where  products  are  treat- 
ed individually  the  composition  found  by  analysis  has  been  stated 
in  terms  conforming  to  those  used  in  the  guaranties. 

PARIS  GREEN. 

Chemically,  Paris  green  is  the  aceto-arsenite  of  copper,  and, 
under  the  provisions  of  the  Federal  Insecticide  Act  and  the  laws 
of  many  states  where  .numerical  standards  for  insecticides  are 
fixed,  this  product  is  deemed  to  be  adulterated :  first,  if  it  does 
not  contain  at  least  fifty  per  cent  of  arsenious  oxide ;  second,  if  it 
contains  arsenic  in  water-soluble  forms  equivalent  to  more  than 
three  and  one-half  per  cent  of  arsenious  oxide;  third,  if  any  sub- 
stance has  been  mixed  and  packed  with  it  so  as  to  reduce  or  lower 
or  injuriously  affect  its  quality  or  strength. 

From  the  tabulated  analyses  given  in  Table  I  it  is  evident  that 
the  guaranties  conform  to  the  federal  numerical  standards  and 
are  met  with  a  liberal  margin  of  safety  in  all  cases.  The  ratio 
of  copper  oxide  to  arsenious  oxide  in  pure  copper  aceto-arsenite 
is  1  :  1.87.  For  the  products  examined  this  year  this  ratio  is 
closely  approximated  except  in  samples  18445  and  18091, 
where  it  is  about  1  :  2 ;  in  the  two  samples  examined  in  1921  the 
ratio  of' 1  :2  is  considerably  exceeded. 


Paris  Green. 


Arsenious  Oxide,  As203. 

Copper 

Dxide,  CuO. 

Total. 

Water-soluble. 

Station  No. 

Guaranteed 

Guaranteed 

Guaranteed 

Found. 

not  less  than. 

Found. 

not  more  than. 

Found. 

not  less  than. 

% 

% 

% 

% 

% 

% 

57-92 

50.00 

I.98 

3-5o 

28.85 



18445 

5940 

50.00 

2.57 

3-5o 

29.65 

1 809 1 

55-94 

5O.00 

I.98 

3-50 

29-65 

.... 

18458 

55-69 

50.00 

1-58 

3-50 

29-45 

.... 

18099 

56.18 

50.0O 

1. 19 

3-5o 

29-45 

.... 

l8l00 

55-69 

50.00 

I.98 

3-50 

30.25 

.... 

18443 

54-95 

50.0O 

2-37 

3-50 

28.85 

29.00 

18090 

55-69 

50.00 

2-57 

3-50 

29.65 

.... 

18455 

56.00 

•     . 

26.80 

17320 

56.50 

.... 

26.60 

.... 

I93I9 

150  CONNECTICUT  EXPERIMENT  STATION  BULLETIN  242. 

ARSENATE  OF  LEAD. 

Chemically,  commercial  arsenate  of  lead  consists  of  products 
derived  from  arsenic  acid  by  replacing  one  or  more  hydrogen 
atoms  by  lead.  The  Federal  Insecticide  Act  deems  arsenate  of 
lead  to  be  adulterated:  first,  if  it  contains  more  than  fifty  per 
cent  of  water;  second,  if  it  contains  total  arsenic  equivalent  to  less 
than  twelve  and  one-half  per  cent  of  arsenic  oxide  (AS2O5)  ; 
third,  if  it  contains  arsenic  in  water-soluble  forms  equivalent  to 
more  than  seventy-five  one-hundredths  per  cent  of  arsenic  oxide 
(AS2O5)  ;  fourth,  if  any  substances  have  been  mixed  and  packed 
with  it  so  as  to  reduce,  lower,  or  injuriously  affect  its  quality  or 
strength;  provided,  howeifer,  that  extra  water  may  be  added  to 
lead  arsenate   (as  described  in  this  paragraph),  if  the  resulting 


Table  II.    Analyses  of 


■i 

Station  No. 

Date. 

18452 

1922 

18451 

1922 

18456 

1922 

18454 

1922 

18088 

1922 

18094 

1922 

I8I02 

1922 

18459 

1922 

1844I 

I922 

18105 

1922 

18106 

1922 

18449 

1922 

18089 

1922 

l8lIO 

1922 

18447 

1922 

209201 

1908-9 

205641 

1908-9 

221631 

1908-9 

223821 

1908-9 

2270I1 

1908-9 

1913 

19373 

1922 

Brand,   Manufacturer   or  Distributor. 


Sampled  by  Station  Agent: 
Acme  White  Lead  &  Color  Works,  Detroit.    Acme. 

Bowker  Insecticide  Co.,  Boston.     Bowker's  

Corona  Chemical  Co.,  Milwaukee.    Corona  Dry  .... 

Detroit  White  Lead    Works,  Detroit.     Rogers. 

Devoe  &  Raynolds  Co.,  Inc.,  New  York.     Devoe... 

General  Chemical  Co.,  New  York.     Orchard   

The  Glidden  Co.,  Cleveland.    Glidden 

The  Grasselli  Chemical  Co.,  Cleveland.     Paste 

Interstate  Chemical  Co.,  Jersey  City.    Key-Dry 

Leggett  &  Brother,  New  York 

Leggett  &  Brother,  New  York  

Merrimac  Chemical  Co.,  Boston.     Swift's  

Nitrate  Agencies  Co.,  New  York.    Naco 

Powers-Weightman-Rosengarten   Co.,  Philadelphia. 
The  Sherwin-Williams  Co.,  Cleveland 

Sampled  by  Purchaser: 

Disparene    

Grasselli  Chemical  Co 

Grasselli  Chemical  Co 

Thomsen  Chemical  Co 

Thomsen  Chemical  Co 

Merrimac  Chemical  Co.,  Boston.    Swift's  

Brand  and  Mfr.  not  known.     Sent  by  Count}'  Agent, 
Middletown 


1  Conn.  Exp.  Sta.  Report  1911,  p.  218. 

2  Conn.  Exp.  Sta.  Report  1913,  p.  305. 


ARSENATE  OF  LEAD. 


151 


mixture  is  labeled  lead  arsenate  and  water,  the  percentage  of  extra 
water  being  plainly  and  correctly  stated  on  the  label. 

Most  of  the  samples  examined  this  year  were  in  powder  form. 
From  the  analyses  given  in  Table  II  it  appears  that  all  samples 
meet  the  requirements  of  their  guaranties  with  respect  to  the  active 
ingredient.     One  sample  contains  a  slight  excess  of  water. 

The  method  of  stating  guaranties  is  not  uniform  as  regards  the 
chemical  terms  used.  The  arsenic  content  is  sometimes  stated  in 
terms  of  the  metal  and  in  other  cases  in  terms  of  the  oxide;  and 
it  is  not  always  clear  which  form  is  indicated  in  stating  the  limit 
of  water-soluble  arsenic.  Uniform  practice  in  this  respect  would 
enable  purchasers  to  compare  statements  of  composition  more 
readily  and  save  the  analyst  some  uncertainty. 


Arsenate  of 

Lead. 

Water. 

Arsenic  Oxide,  As205. 

Lead  Oxide,  PbO. 

Total. 

Water-soluble. 

Station 
No. 

Guaranteed 

Guaranteed 

Guaranteed 

Guaranteed 

Found. 

not  more 

Found. 

not  less 

Found. 

not  more 

Found. 

not  less 

than. 

than. 

than. 

than. 

% 

% 

% 

% 

% 

% 

% 

% 

.... 

.... 

33-12 

30.0O 

0.14 

1. 00 

63.65 

.... 

18452 

.... 

.... 

30.59 

30.00 

O.38 

O.77 

66.31 

.... 

18451 

.... 

.... 

32.20 

30.00 

0.18 

O.77 

64.25 

18456 

.... 

.... 

3I-5I 

30.00 

0.18 

I. OO 

63.23 

18454 

.... 

.... 

32.66 

31.00 

0-97 

I. OO 

63.65 

63.OO 

18088 

.... 

.... 

31-74 

30.00 

0.l8 

1.50 

65.07 

.... 

18094 

.... 

.... 

31-97 

31.00 

0.44 

O.77 

6346 

.... 

I8I02 

43-73 

50.OO 

17.80 

15.00 

O.29 

0-50 

36.47 

.... 

18459 

.... 

.... 

31-74 

30.00 

0.28 

0.75 

61.86 

.... 

18441 

44-23 

50.00 

18.03 

14.00 

O.I  I 

0-75 

36.43 

30.00 

18105 

.... 

.... 

32.66 

30.00 

0.28 

1. 00 

64.50 

6l.OO 

18106 

50.43 

5O.00 

14.61 

12.50 

0.26 

0.75 

3348 

31-50 

18449 

.... 

.... 

30.59 

30.00 

1. 10 

i-53 

65.50 

62.0O 

18089 

.... 

.... 

32.78 

30.00 

0.77 

2.30 

64.59 

.... 

l8lI0 

.... 

.... 

31.06 

30.00 

0.28 

1. 00 

63.95 

.... 

18447 

36.61 

18.80 

42.05 

20g20 

40.70 

15-24 

.  .  . 

.... 

20564 

45-57 

15-38 

.  .  . 

. . . 

37-25 

22163 

51-73 

[3.81 

.  .  . 

32.04 

22382 

45.76 

16.10 

.  .  . 

. . . 

35-71 

22701 

42.20 

17.67 

37-8i 

.... 

32.18 



64-45 



19373 

152  CONNECTICUT  EXPERIMENT  STATION   BULLETIN   242. 

INSECTICIDES  AND  FUNGICIDES   OTHER  THAN 
PARIS  GREEN  AND  LEAD  ARSENATE. 

The  federal  Act  holds  an  insecticide  or  fungicide  other  than 
Paris  green  and  lead  arsenate  to  be  adulterated :  first,  if  its 
strength  or  purity  falls  below  the  professed  standard  or  quality 
under  which  it  is  sold;  second,  if  any  substance  has  been  substi- 
tuted wholly  or  in  part  for  the  article ;  third,  if  any  valuable  con- 
stituent of  the  article  has  been  wholly  or  in  part  abstracted; 
fourth,  if  it  is  intended  for  use  on  vegetation  and  shall  contain 
any  substance  or  substances  which,  although  preventing,  destroy- 
ing, repelling,  or  mitigating  insects  shall  be  injurious  to  such 
vegetation  when  used. 

The  Act  further  requires  such  of  these  preparations  as  contain' 
arsenic  to  declare  on  the  label  in  terms  of  metallic  arsenic  the 
total  amount  thereof  and  the  amount  in  water-soluble  forms ;  it 
also  requires  to  be  stated  the  name  and  amount  of  each  and  every 
inert  ingredient  or,  in  lieu  of  this,  the  name  and  amount  of  each 
active  ingredient,  together  with  the  total  percentage  of  inert  in- 
gredients. Under  the  laws  of  some  states  an  insecticide  or  fun- 
gicide, other  than  Paris  green  or  lead  arsenate,  is  misbranded  if 
it  does  not  declare  the  name  and  percentage  of  each  and  every 
active  ingredient. 

Calcium  Arsenate. 

18101.     The  Glidden  Co.,  Cleveland,  O. 

This  sample  was  found  by  analysis  to  be  arsenate  of  lead  in- 
stead of  arsenate  of  calcium,  evidently  a  mistake  in  labeling  or 
packing. 

Copper-Calcium  Arsenate. 

19136.  Copper-Calcium  Arsenate  dust,  13-8-79.  Dosch 
Chemical  Co.,  Louisville,  Ky.  Stock  of  the  department  of  ento- 
mology of  this  Station. 

Analysis : 

Found.   Guaranteed. 
%  % 

Copper,  metallic 5-20  4.40  (not  less    than) 

Arsenic  oxide,  total  1.39  3-00  (not  less    than) 

Arsenic,  metallic,  water-soluble   ...  0.50  (not  more  than) 

19428.  Niagara  Potato  Dust  Mixture.  Labeled  as  contain- 
ing monohydrated  copper  sulphate,  19.5  per  cent;  tricalcium  ar- 
senate, 17.5  per  cent,  and  inert  ingredients,  63  per  cent. 


BORDEAUX    MIXTURE LEAD    ARSENATE. 


153 


Analysis 


Copper,    metallic     

Arsenic,    metallic     

Arsenic,    water    soluble,    metallic 


Found.  Guaranteed. 
%  % 

7-97  6.95 

5-28  6.25 

0.50 


Bordeaux  Mixtures. 

18104.    Anchor  Brand.    Leggett  and  Brother,  New  York. 

18108.    The  Grasselli  Chemical  Co.,  Cleveland,  O. 

18448.     Sterlingworth.     Sterling  Chemical  Co.,  Cambridge, 
Mass. 

Table  III.    Analyses  of  Bordeaux  Mixture's. 


Condition. 

Water. 

Copper,  Metallic. 

Station  No. 

Found. 

Guaranteed 
not  less  than. 

18104 
18108 
18448 

Paste 
Dry 
Dry 

% 
58.03 

% 
4-79    ■ 
14.78 
II.96 

% 

4-50 
13.00 
10.00 

Bordeaux  Mixture — Paris  Green. 

18107.     Leggett  and  Brother,  New  York. 
18093.    Naco.    Nitrate  Agencies  Co.,  New  York. 

Table  IV.    Analyses  of  Bordeaux — Paris  Green. 


Copper 

Oxide,  CuO. 

Arsenioii9  Oxide,  AS2O3. 

Found. 

Guaranteed 
not  less  than. 

Total. 

Water-soluble. 

Station  No. 

Found. 

Guaranteed 
not  less  than. 

Found. 

Guaranteed 
not  more  than. 

18107 
18093 

% 

17-37 
16.23 

% 
I7-50 
18.OO 

% 
17.69 
17.32 

% 
16.50 
17.OO 

% 
2.72 
O.82 

% 

2.641 
2.0O 

1  Calculated  from  amount  guaranteed  as  metallic  arsenic. 


Bordeaux  Mixture — Lead  Arsenate. 

18111  and  18442.  Key  Brand  Bordo-Lcad.  Interstate 
Chemical  Co.,  Jersey  City,  N.  J. 

18096.  Gliddcn  Bordo- Arsenate.  The  Glidden  Co.,  Cleve- 
land, O. 


154  CONNECTICUT  EXPERIMENT  STATION  BULLETIN  242. 

Table  V.  Analyses  of  Bordeaux — Lead  Arsenate. 


Condi- 
tion. 

Water. 

Arsenic  Oxide,  As205. 

Copper 

Oxide, 

CuO. 

Total. 

Water-soluble. 

Lead 

Oxide, 

PbO. 

Station  No. 

Found. 

Guaranteed 

not  less 

than. 

Found. 

Guaranteed 
not  more 
than. 

18111 
18442 
18096 

Paste 
Paste 
Dry 

% 
60.85 
60.83 

% 
6.65 
7.82 

17-54 

% 

4451 
7.671 
15-50 

% 
O.60 
O.09 
0.20 

% 
0.771 
0.771 
O.5O1 

% 

7-57 

3-74 

11.66 

% 
1376 

31-71 

1  Calculated  from  amount  guaranteed  as  metallic   arsenic. 


Bordeaux  Mixture — Zinc  Arsenite. 

19729.     Zinc  Bordeaux,   Orchard  Brand,  General  Chemical 
Co.,  New  York. 

Analysis : 

Found.   Guaranteed. 


% 

Arsenic,  total,  metallic   10.22 

water-soluble,    metallic    . . .  0.25 

Copper,  metallic   16.07 

Zinc,  metallic   I4-41 

1  Guaranteed  zinc  arsenite  30.00. 


% 

10.16  (not  less    than) 

100  (not  more  than) 

15.70  (not  less    than) 

i3.3i1(not  less    than) 


Nicotine  Products  and  Tobacco. 

19748.     Black  Leaf  40.    Tobacco  By-Products  and  Chemical 
Corporation,  Inc.,  Louisville,  Ky.     Sampled  by  Station  agent. 
Nicotine  found  40  per  cent ;  guaranteed  40  per  cent. 

19370.  Black  Leaf  40.  Sample  submitted  by  department  of 
entomology  of  this  Station. 

Nicotine  found  40.70  per  cent ;  guaranteed  40  per  cent. 

19608.    Jebl.     Made  by  J.  H.  Rice,  Ashtabula,  O. 
This  is  an  emulsion  guaranteed  to  contain  nicotine  0.80  per 
cent  and  inert  ingredients  99.20  per  cent. 

Partial  analysis  showed  the  following  composition : 

Water  and  volatile  at  ioo°  C 79-29% 

Solids    20.71 

Ash 7-85 

Nicotine  (as  alkaloid) 1.08 

19152.  Garden  Dust.  Dosch  Chemical  Co.,  Louisville,  Ky. 
The  sample  was  submitted  by  the  Station  department  of  entomol- 
ogy.   It  is  a  mixture  of  lead  arsenate,  sulphur  and  nicotine,  but 


NICOTINE  PRODUCTS  AND  TOBACCO.  1 55 

was  examined  only  for  nicotine.     Nicotine  found  2.24  per  cent ; 
guaranteed  2.00  per  cent. 

19427.  Niagara  Nicotine  Contact  Mixture.  Niagara  Sprayer 
Co.,  Middleport,  N.  Y.  Sampled  by  the  Station  agent.  Nicotine 
found,  2.38  per  cent ;  guaranteed,  2.20  per  cent. 

19658.  Tobacco  Dust.  Hall  Tobacco  Chemical  Co.,  St.  Louis, 
Mo.  The  sample  was  submitted  by  E.  M.  Ives,  Meriden.  Sixty 
per  cent  passed  a  200  mesh  sieve.  Nicotine  content  found,  1.30 
per  cent. 

19742.  Tobacco  Dust.  Sample  submitted  to  the  Station  en- 
tomologist by  Lewis  Cheeseman,  Hatfield,  Mass. 

The  sample  was  examined  as  follows : 

Total  ash  39.60% 

Ash  insoluble  in  dil.  acid  (sand,  etc.)    15-30     ' 

Nitrogen    1.99 

Nicotine  (as  alkaloid)    1.72 

19099  and  19100.  Tobacco  Dust.  Submitted  by  Prof.  G. 
H.  Lamson,  Storrs.  The  samples  contained  1.09  and  0.50  per  cent 
of  nicotine  respectively.    . 

19188.  Low  Grade  Leaf  Tobacco.  Supplied  by  L.  B.  Hass 
Co.,  Hartford. 

Partial  analysis  showed  the  following  composition : 

Moisture     5.63% 

Ash,  crude    20.13 

Nitrogen,  in  nitrates   1.17 

in  ammonia    0.77 

in  nicotine  0.55 

in  other  organic  matter  1.89 

Ether  extract  3-98 

Nicotine  3-!0 

Analysis  of  the  crude  ash  showed  the  following  composition : 

Sand,  silica,  etc : 22.67% 

Iron  and  aluminum  (Fe203  and  A1203)   1.86 

Manganese   (Mn304)    0.62 

Magnesium   (MgO) 4-69 

Calcium  (Ca6)    20.74 

Potassium    (K20) 22.44 

Sodium    (NaaO)    0.80 

Sulphuric    acid    (S03)     •' 6.09 

Chlorine  (CI) 0.71 

Phosphoric   acid    (P2Os)    3-62 

Carbonic   acid    (C02)    ._ 14-50 

Undetermined  including  moisture 1.26 

Deduct  oxygen=chlorine    0.16 

Total 100.00 


I56  CONNECTICUT  EXPERIMENT  STATION  BULLETIN   242. 

ClCARETTES. 

In  connection  with  a  study  of  methods  for  the  determination  of 
nicotine  in  tobacco  and  other  products  a  number  of  brands  of 
cigarettes  were  examined. 

Table  VI.    Analyses  of  Cigarettes. 


Station  No. 

Brand. 

Loss  at  100  °C. 

Ash. 

Nitrogen. 

Nicotine. 

% 

% 

% 

% 

19298 

Lucky  Strike 

7-63 

16.54 

2.23 

I.83 

19311 

Melachrino 

7-34 

17-74 

2.58 

1-43 

19316 

Camel 

7.98 

IS-30 

2.24 

1.80 

I93I7 

Fatima 

8.25 

13-63 

I.99 

1.72 

19318 

Murad 

7-33 

17.14 

2.72 

1.46 

Hellebore. 

19730.  White  Hellebore  Root.  J.  L.  Hopkins  &  Co.,  New 
York. 

19736.  Key  Brand  Hellebore.  Interstate  Chemical  Co.,  Jer- 
sey City,  N.  J. 

18109.  Anchor  Brand  Hellebore.  Leggett  &  Brother,  New 
York. 

18098.  Hellebore  Root.    S.  B.  Penick  &  Co.,  New  York. 

19731.  Hellebore  Root  Powder.  S.  B.  Penick  &  Co.,  New 
York. 

Table  VII.    Analyses  of  Hellebore. 


Ash. 

Total  alkaloids. 

Total 
nitrogen. 

Station  No. 

Insol. 

Guaranteed 

Total. 

in  acid. 

Found. 

not  less  than. 

% 

% 

% 

% 

% 

19730 

H.83 

6.97 

I.07 

0.79 

I.2I 

19736 

IO.56 

5-03 

1-43 

0.25 

I.29 

18109 

7-50 

3-23 

1.26 

0.20 

i-59 

18OQ8 

9-25 

5-40 

1.27 

I.I4 

I973I 

4.46 

1.05 

2.70 

I. OO 

1.48 

The  method  used  for  the  determination  of  alkaloids  of  Vera- 
trum  (hellebore),  was  as  described  by  Viehoover  and  Clevenger1. 


Miscellaneous  Insecticides  and  Fungicides. 

The  following  spray  materials  were  made  by  the  Niagara  Spray- 
er Co.,  Middleport,  N.  Y.  and  were  sampled  by  the  Station  agent 
from  the  stock  of  H.  D.  Peters,  Highwood. 

JJour.  Am.  Phar.  Assoc, -11,  3,  169,  March  1922. 


MISCELLANEOUS  INSECTICIDES  AND  FUNGICIDES.  1 57 

19425.  Niagara  Potato  Dust  Mixture,  without  poison.     La- 
beled monohydrated  copper  sulphate,  19.5 ;  inert  ingredients,  80.5. 

Analysis : 

•Found.     Guaranteed. 
Copper,  metallic 7.56%  6.50% 

19426.  Niagara  "All  in  One."    Labeled  sulphur,  19;  nicotine, 
1.1;  lead  arsenate,  9.5;  Bordeaux,   19;  inert  ingredients,  51.4. 

Analysis-: 

Found.     Guaranteed. 

%  % 

Copper,  metallic 6.30  4.00 

Arsenic,  metallic    .'.          1.82  1.80 

Arsenic,  water-soluble  ...  0.50 

Nicotine    1..11  1.10 

19429.  Niagara  80-10-10   Mixture.     Labeled   sulphur,    78; 
lead  arsenate,  9.8;  inert  ingredients,  12.2. 

Analysis : 

Found.  Guaranteed. 
%  % 

Arsenic,  metallic 2.26  1.95 

Arsenic,  water-soluble ...  0.50 

19430.  Niagara  85-15  Dusting  Mixture.     Labeled  sulphu/ 
83;  lead  arsenate,   14.70;  inert  ingredients,  2.30. 

Analysis : 

Found.  Guaranteed. 
%  % 

Arsenic,  metallic    3.02  2.92 

Arsenic,  water-soluble   ...  0.50 

Other  miscellaneous   materials  sampled  by  the   Station  agent 
are  as  follows : 

18453.  Pyrox.    Bowker  Insecticide  Co.,  Boston. 

18446.  Naco  Kalibor.    Nitrate  Agencies  Co.,  New  York. 

18086.  Hexpo.    H.  J.  Smith  &  Co.,  Utica,  N.  Y. 

19739.  Key-Cide.    Interstate  Chemical  Co.,  Jersey  City. 


158  CONNECTICUT  EXPERIMENT  STATION  BULLETIN  242. 


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MISCELLANEOUS  INSECTICIDES  AND  FUNGICIDES.  1 59 

18450.  Slug  Shot.  Hammond's  Slug  Shot  Works,  Beacon, 
N.  Y. 

Analysis : 

Found.     Guaranteed. 
%  % 

Sulphur   ...  6.00 

Arsenic,  metallic    0.89  0.79 

Water-soluble  arsenic,  metallic   0.12  trace 

Copper,  metallic 1.01  0.911 

Nicotine    '.  .         0.04  trace 

Carbolic  acid,  crude present  0.40 

18087.     Bug  Death.      Danforth   Chemical   Co.,  Leominster, 
Mass. 
Analysis : 

Found.  Guaranteed. 

%  % 

Zinc  oxide 54-15  47.00 

Lead  oxide    « 14.1 1  5.00 

18092.  Sterlingzvorth  Cut  Worm  Killer.  Sterling  Chemical 
Co.,  Cambridge,  Mass. 

Analysis : 

Found.     Guaranteed. 

Arsenious  oxide 1.99  1.00  (not  less    than) 

Water-soluble   arsenic,   metal 1.40  0.07  (not  more  than) 

The  arsenic  in  this  sample  is  largely  in  water-soluble  form. 

18444.     He-Bo.    Sterling  Chemical  Co.,  Cambridge,  Mass. 
Analysis : 

Found.  Guaranteed. 

%  %     ■ 

Barium  carbonate   34-41  36.00 

Arsenic,  metallic   1.35  2.00 

Arsenic,  water-soluble,  metal   0.12  0.30        . 

18103.'  Mag-O-Tite.    Randall-McLaughlin,  Seattle,  Wash. 
Analysis : 

Found.  Guaranteed. 

%  %     ■ 

Arsenic,  metallic    ...  0.06 

Arsenic,  water-soluble,  metal   0.06  0.002 

Napthalene     6.35  4.39 

Napthalene  was  determined  by  extracting  the  material  with 
ether,  dissolving  the  ether  extract  in  boiling  95  per  cent  alcohol 
and  precipitating  the  napthalene  by  means  of  a  saturated  solu- 

1  Calculated  from  copper-sulphate  and  copper  arsenite  guaranteed. 


l6o  CONNECTICUT  EXPERIMENT  STATION  BULLETIN   242. 

tion  of  picric  acid.    The  naphthalene  picrate  was  dried  at  50°  C. 
and  weighed1. 

18457.  .Sulfocide.    B.  G.  Pratt  Co.,  New  York. 
This  is  a  liquid  fungicide  guaranteed  to  contain  30  per  cent  of 
sulphur  combined  as  sodium  polysulphide  and  sodium  thiosulphate. 
Analysis  showed  the  following  distribution  of  sulphur2 : 

Sulphur,  total 29.25% 

as   thiosulphate  ' 1.84 

as  sulphate 0.10 

as  sulphide,  by  diff 27.31 

The  following  miscellaneous  materials  were  submitted  from 
various  sources : 

19173.  Nickel  Carbonate.  Submitted  by  the  Station  ento- 
mologist. 

It  was  found  to  contain  44.64  per  cent  of  nickel,  which  is  equiva- 
lent to  90.28  per  cent  of  nickel  carbonate.  The  material  contained 
also  a  trace  of  sulphates.  Nickel  was  determined  by  the  dimethyl- 
glyoxime  method3. 

172  57.  Borecide.  Mason  Drug  and  Chemical  Co.,  Hancock, 
Md. 

According  to  descriptive  literature  concerning  this  insecticide, 
the  vapors  which  it  gives  off  are  toxic  to  borers  and  other  tree 
pests. 

Partial  analysis  was  made  as  follows : 

Ash    58.14% 

Loss  on  ignition   41.86 

Insoluble  in  boiling  water  65.35 

M.  P.  of  sublimate   3i.o°C. 

The  material  has  the  odor  of  naphthalene  and  the  sublimate 
combined  with  picric  acid.  The  melting  point,  however,  was  not 
correct  for  naphthalene,  but  approximated  that  of  the  methyl  de- 
rivative. 

19732.  M editings  P.  T.  B.  Mechling  Bros.  Mfg.  Co,  Cam- 
den, N.  J. 

This  is  a  preparation  of  paradichlorobenzine,  the  vapors  of 
which  are  destructive  to  peach  tree  borers  and  other  tree  pests. 
The  melting  point  of  the  compound  was  observed  to  be  56°C. 

19683  and  19684.  Fish  Oil  Soap.  Made  by  the  General 
Chemical  Co,  New  York,  and  submitted  by  the  Station  ento- 
mologist.    Differentiated  by  the  sodum  cobaltinitrite  and  potas- 

1  Allen  Comm.  Org.  Analysis,   3,  p.   243  et  seq. 

Mulliken.     Identification   of  Pure  Organic   Compounds,   1,  p.   201. 

2  Analysis  by  H.  J.  Fisher. 

3  Griffin,  Technical  Methods  of  Analysis,  p.   121. 


MISCELLANEOUS  INSECTICIDES  AND  FUNGICIDES.  l6l 

sium  pyroantimonate  tests,  19683  was  indicated  to  be  a  soda 
soap,  while  19684  was  indicated  to  be  largely  a  potash  soap. 

18898.  A  paste  made  by  the  Garden  Chemical  Co.,  New  York, 
and  examined  for  the  Station  entomologist.  It  appeared  to  be 
composed  largely  of  an  emulsion  of  soap  and  pyridine. 

Dusting  Powder,  made  by  the  Niagara  Sprayer  Co.,  Middle- 
port,  N.  Y.,  was  submitted  by  E.  M.  Ives,  Meriden.  By  the  U.  S. 
P.  assay  it  contained  99.09  per  cent  of  sulphur;  98.2  per  cent  of 
the  powder  passed  a  200  mesh  sieve. 

19404.  Bordeaux  mixture,  thought  to  have  decomposed  or  to 
have  been  mixed  with  other  material.  The  sample,  which  was  a 
black  powder,  contained  24.02  per  cent  of  calcium  oxide  and  21.23 
per  cent  of  copper,  largely  in  the  form  of  cupric  oxide. 

19339.  Bees  and  19340,  Soil,  submitted  by  O.  N.  White- 
head, Wallingford.  The  bees  were  thought  to  have  been  killed 
by  arsenical  spray  on  blossoms  of  peach  trees.  No  conspicuous 
amounts  of  arsenic  were  found  in  either  the  bees  or  the  soil. 

18095.  Kayso.  California  Central  Creameries,  San  Fran- 
cisco. A  prepared  casein  spreader  to  be  used  with  spraying  mix- 
tures. The  material  contained  25.26  per  cent  of  casein  (calculated 
from  nitrogen  by  the  factor  6.38),  and  73.78  per  cent  of  ash, 
which  consisted  chiefly  of  calcium. 

19492.  Ace-Hy.-  General  Chemical  Co.,  New  York.  The 
active  ingredient  is  not  stated,  but  the  inert  ingredient  is  stated  to 
be  water,  of  which  there  is  not  more  than  40  per  cent.  The  pre- 
paration is  an  emulsion  in  which  a  cyanide,  equivalent  to  2.29 
grams  CN  per  100  cc.  is  the  chief  active  ingredient  detected. 
The  ash,  3.58  per  cent,  consisted  chiefly  of  iron  and  copper  oxides. 
Water  and  volatile  matter  (at  100°  C.),  made  up  77.3  per  cent 
of  the  material. 

Salairacine.     Made  by  J.  D.  McGregor,  Stamford. 

A  sample,  17745,  submitted  by  a  purchaser  in  192 1,  and  one, 
19740,  supplied  by  the  Station  entomologist,  have  been  exam- 
ined as  follows : 

17745  19740 

%  % 

Moisture    0.90  .... 

Insoluble  in  dilute  acid   0.56  .... 

Nitrogen  (in  nitrates)  none  1.95 

Lead  oxide  (PbO)    24.21  .... 

Arsenic    oxide    (As,03)     H-73  10.54 

Oxides   of  iron  and   aluminum   (Fe2Os  and   ALO:,)  .  .            0.50  .... 

Calcium  (CaO)    25.64  17.67 

Magnesium   (MgCO    17-33 

■Carbon  dioxide  (CCO,  by  difference   19-13  •  ■  ■  • 


l62  CONNECTICUT  EXPERIMENT  STATION  BULLETIN  242. 

The  analysis  made  in  192 1  indicated  that  the  material  was  com- 
posed essentially  of  lead  arsenate  and  dolomitic  lime.  The  sam- 
ple analyzed  in  1922  showed  a  considerable  amount  of  nitrogen  in 
nitrates,  indicating  a  change  in  the  formula.  Advertising  litera- 
ture submitted  with  the  first  sample  states:  "Salairacine  de- 
stroys the  insects  in  the  soil  and  gives  new  life  to  young  and  old 
trees.  It  has  been  used  with  great  success  on  trees  which  were 
absolutely  riddled  with  borers."  It  is  directed  to  loosen  the  soil 
two  inches  deep  around  trees  and  dust  salairacine  into  the  soil;  or 
sprinkle  on  the  surface  of  turf  and  water  thoroughly. 

There  is  nothing  shown  by  our  analyses  to  indicate  any  insecti- 
cidal  value  in  this  product  not  supplied  by  lead  arsenate  as  well; 
or  any  fertilizing  value  not  equally  well  supplied  by  nitrate  of 
soda  and  lime. 

The  following  were  submitted  by  the  Station  entomologist  dur- 
ing 192 1  and  are  cited  from  Bulletin  233  of  this  laboratory,  p.  109 : 

16420.    "Sulco-V.  B."    Contained  3.97  per  cent  of  phenol. 

16740.  Niagara  Contact  Special  Dusting  Mixture  was  found 
to  contain  1.62  per  cent  nicotine. 

Four  nicotine  mixtures  were  found  to  contain  0.29,  0.30,  0.84 
and  0.71  per  cent  of  nicotine. 

16946.  Formaldehyde  solution  submitted  by  the  Station  bot- 
anist, was  found  to  contain  33.7  per  cent  of  formaldehyde  by 
weight. 


II.    Recent  Developments  in  the  Use  of  Insecticides. 

By  W.  E.  Britton,  Entomologist. 

In  connection  with  the  analyses  reported  in  the  preceding  pages, 
it  might  be  well  to  call  attention  to  some  tendencies  of  the  present 
day  in  the  use  of  insecticides  and  fungicides.  In  1907,  when  Bul- 
letin 157  was  published,  no  arsenical  poisons  were  used  except 
paste  lead  arsenate  and  Paris  green.  At  the  present  time  to  kill 
chewing  insects,  most  Connecticut  orchardists  and  vegetable  grow- 
ers prefer  and  use  lead  arsenate  in  its  dry  or  powdered  form, 
which  is  easier  to  handle  and  seems  to  be  just  as  effective.  As  an 
insecticide,  Paris  green  has  largely  been  replaced  by  lead  arsen- 
ate. Moreover,  several  other  poisons  are  now  on  the  market,  such 
as  calcium  arsenate,  copper-calcium  arsenate,  and  zinc  arsenite 
which  are  sometimes,  though  probably  not  extensively,  used. 

In  1907,  nicotine  sulphate  preparations  were  little  used,  whereas 
now  they  have  come  into  almost  universal  use  to  kill  sucking  in- 
sects. Casein  spreaders  were  then  unknown  and  are  now  coming 
into  rather  general  use.  Dusting  in  orchards  is  a  recent  practice 
in  Connecticut,  which  will  probably  not  wholly  supplant  spray- 
ing; and  there  are  many  proprietary  insecticides  and  fungicides 
now  on  the  market,  and  many  possible  and  advantageous  combina- 
tions of  standard  materials,  unheard  of  fifteen  years  ago.  Like- 
wise in  those  days  the  lime-sulphur  mixture  was  used  only  as  a 
dormant  spray  to  kill  San  Jose  scale,  but  now  this  mixture  dilut- 
ed as  a  summer  spray'  is  the  most  common  fungicide  used  on  the 
foliage  in  Connecticut  apple  orchards. 

Arsenical  Poisons. 

Arsenical  insecticides  are  commonly  employed  as  stomach  poi- 
sons to  kill  chewing  insects,  such  as  grasshoppers,  caterpillars  and 
leaf-beetles.  The  poison  is  placed  upon  the  food  plant,  and  must 
be  swallowed  by  the  insect  in  order  to  be  effective  as  an  insecti- 
cide. Lead  arsenate  is  by  far  the  most  common  one  now  in  use, 
is  generally  non-injurious  to  the  plant,  and  may  be  applied  as  a 
dust  or  in  liquid  form  at  the  rate  of  one  ounce  of  paste  or  one- 
half  ounce  of  the  powder  in  a  gallon  of  water.  This  is  nearly 
equivalent  to  three  pounds  of  the  paste  or  one  and  one-half  pounds 
of  the  powder  in  a  barrel  holding  fifty  gallons. 

Paris  green  contains  a  sufficient  amount  of  water-soluble  ar- 
senic to  be  generally  unsafe  for  vegetation  except  in  the  presence 
of  lime.  Lime  should  also  be  added  to  a  mixture  of  calcium  arsen- 
ate when  used  on  most  kinds  of  foliage,  but  both  Paris  green  and 


164  CONNECTICUT  EXPERIMENT  STATION   BULLETIN  242. 

calcium  arsenate  may  be  used  in  combination  with  Bordeaux 
mixture  on  potatoes  without  fear  of  injury.  Several  times  in  our 
Station  tests  calcium  arsenate  has  injured  apple  foliage  even  where 
lime  was  added.  Zinc  arsenite  was  used  as  a  poison  on  ten  rows 
of  potatoes  at  the  Station  Farm  at  Mount  Carmel  in  1914,  in 
comparison  with  lead  arsenate.  Both  killed  the  larvae  of  the 
Colorado  potato  beetle,  and  there  was  no  injury  to  the  foliage. 
Magnesium  and  barium  arsenates  have  not  been  used  in  Station 


tests. 


Hellebore. 


Hellebore  is  the  powdered  rootstock  of  an  herbaceous  plant, 
Veratrum.  It  acts  as  a  stomach  poison  and  has  slight  value  as  a 
repellant.  Its  virtue  depends  upon  a  volatile  alkaloid ;  hence  only 
fresh  material  should  be  used.  The  larvae  of  the  sawflies,  like 
the  currant  worm,  are  particularly  susceptible  to  death  from  eat- 
ing it.  It  may  be  applied  dry  and  undiluted  or  mixed  with  water 
at  the  rate  of  one  ounce  in  two  gallons. 


&*- 


Nicotine  Preparations. 

Though  nicotine  is  a  stomach  poison  if  taken  in  sufficient 
amounts,  it  is  chiefly  employed  to  kill  sucking  insects  by  contact. 
It  is  often  used  in  the  form  of  tobacco  dust,  finely  ground,  but  as 
tobaccos  vary  widely  in  their  nicotine  content  and  few  manufac- 
turers have  attempted  to  place  a  uniform  product  on  the  market, 
nicotine  is  generally  purchased  as  a  liquid  in  the  form  of  nicotine 
sulphate  containing  40  per  cent  nicotine.  There  are  several 
commercial  preparations  on  the  market  sold  under  trade  names, 
"Black  Leaf  40"  being  one  of  those  best  known  in  Connecticut. 
When  diluted  at  the  rate  of  one  teaspoonful  per  gallon,  or  one- 
half  pint  per  barrel,  and  applied  as  a  spray,  it  will  kill  most  soft- 
bodied  aphids,  but  this  quantity  may  need  to  be  doubled  to  kill 
some  other  sucking  insects.  Even  in  stronger  applications  it  does 
not  injure  most  kinds  of  foliage.  When  used  alone  it  is  more 
effective  if  cpmmon  laundry  soap,  one-half  ounce  per  gallon,  or 
two  pounds  per  barrel,  is  dissolved  and  added,  but  this  is  un- 
necessary when  used  with  calcium  caseinate  or  with  lime-sulphur. 

Combinations  of  Insecticides  and  Fungicides. 

Though  each  different  material  may  be  recommended  and  used 
to  control  some  particular  pest,  the  grower  cannot  conveniently 
make  a  separate  application  for  this  purpose,  and  has  practiced 
applying  them  in  combination  to  control  those  chewing  and  suck- 
ing insects  and  fungi  which  may  simultaneously  attack  his  crops. 
For  instance,  he  can  combine  lead  arsenate,  nicotine  solution  and 


COMBINATION    OF    INSECTICIDES    AND    FUNGICIDES.  165. 

Bordeaux  mixture  to  form  the  best  general  application  for  pota- 
toes. Calcium  arsenate  may  be  substituted  for  lead  arsenate  at  a 
saving  in  cost,  but  by  such  a  combination  thoroughly  applied,  the 
grower  may  effect  a  reasonable  degree  of  control  over  the  Colo- 
rado beetle,  aphids,  leafhoppers,  and  the  blight.  Bordeaux  mix- 
ture is  still  the  most  effective  fungicide  on  the  potato. 

In  Connecticut  apple  orchards,  Bordeaux  mixture  is  not  em- 
ployed to  the  same  extent  as  was  the  case  a  few  years  ago  on  ac- 
count of  its  effect  in  russeting  the  fruit.  Liquid  lime-sulphur 
(diluted  1  to  40)  is  now  generally  used  in  its  place  on  the  foliage. 
Some  trouble  results  from  an  indiscriminate  mixing  of  lime-sul- 
phur with  lead  arsenate  and  nicotine,  but  this  may  be  avoided  in 
large  measure  by  mixing  in  the  proper  order  and  by  the  use  of  a 
calcium  caseinate  spreader.  The  best  results  are  obtained  when 
these  materials  are  placed  in  the  spray  tank  in  the  following 
order : 

t.     Clean  water. 


Nicotine  sulphate. 
Calcium  caseinate  (if  used). 
Lead  arsenate. 
Lime-sulphur. 


There  is  usually  some  discoloration  when  lime-sulphur  and  lead 
arsenate  are  put  together,  and  this  sometimes  approaches  a  brown 
color  due  to  lead  sulphide  being  formed.  If  the  nicotine  is  then 
thrown  into  this  mixture  it  will  often  be  precipitated  in  masses  of 
brown  sludge,  which  will  clog  the  pump  and  coat  the  tank.  When 
mixed  in  the  order  shown  above,  particularly  with  the  calcium 
caseinate  spreader,  little  or  no  discoloration  follows,  and  a  clear 
yellow  mixture  results.  The  spreader  is  also  of  material  assist- 
ance in  coating  the  whole  surface  with  a  thin  film  of  the  spray 
mixture;  otherwise,  it  is  apt  to  collect  in  drops.  The  spreader, 
therefore,  insures  better  protection  to  the  foliage,  makes  the  mix- 
ture go  further,  and  prevents  chemical  changes  from  occurring 
when  the  different  ingredients  are  mixed  together. 


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